The most commonly known conventional manufacturing process of the cellulose fiber is a viscose process. However, the popularity of such viscose process is gradually declined due to the fact that the viscose process has too many processing steps and produces carbon disulfide CS.sub.2 and sulfur dioxide SO.sub.2 that will cause serious environment pollution during the production process.
Recently, a new non-polluting manufacturing process called cellulose solvent spin process (also known as solvent process) has been used to mass-produce the cellulose fiber. The advantages of the cellulose solvent spin process include that:
(1) it will not produce pollution during the production process; PA1 (2) it has a simple and relatively short process; PA1 (3) it is excellent for mass production; PA1 (4) it has a low manufacturing costs; PA1 (5) it can produce high quality final product. PA1 (a) adding a predetermined amount of pulp cellulose and polymerization anti-decay additive into a mixing chamber; PA1 (b) fully mixing a predetermined proportion of a N-methyl morpholine oxide and a N-methylolcaprolactam to form a cellulose solvent; PA1 (c) evenly mixing a predetermined amount of the cellulose solvent, a predetermined amount of water, the pulp, and the additive in the mixing chamber to form a cellulose slurry, wherein pulp fibers of the pulp are fully swelled; and PA1 (d) removing the water in the cellulose slurry by means of a film type evaporator, so that a cellulose solution with low viscosity is obtained.
However, the cellulose solvent spin process also has a critical shortcoming, that is the viscosity of the cellulose solution produced is as high as 12000 poise to 30000 poise. It is well known that the cellulose solution with high viscosity would cause spinning difficulties. The only solution available now is either to lower the concentration of the cellulose in solution or increase the spinning temperature. By lowing the concentration of the cellulose not only slows down the production rate, but also requires more solvent volume that results in increasing of the manufacturing cost. High spinning temperature would easily result in largely reducing the cellulose polymerization degree that would reduce the strength of the final product. The above mentioned dilemmas of the cellulose solvent spin process is still the technicality that needs to be improved before the cellulose solvent spin process becomes a profitable process.
Furthermore, the dimethyl sulfoxide (DMSO) is one of the raw materials that has been studied in the laboratory for improving the viscose process, but because it is not easy to obtain the pure dimethyl sulfoxide and fails to achieve satisfactory effect, the dimethyl sulfoxide still can not meet the industry standard.